Vladimir Putin has given his clearest hint yet that he is preparing to get back his old job as president during a masterful performance at his annual question and answer session with the Russian public.

Putin, currently prime minister, spent more than four hours answering carefully screened questions from across Russia on subjects including the Lada car and whether the Iranians have built a nuclear bomb yet. Asked by a mining student whether he wanted to be president again, Putin replied: "I will think about it," adding "There's still plenty of time."

Ever since he made way for Dmitry Medvedev to take over the presidency in 2008 after eight years in office, there has been speculation that he is planning to return at the next presidential election in 2012. Today Putin did nothing to dispel the impression that he is Russia's most accomplished and popular politician – and that it is he who actually runs the country. Most of his questioners apparently agreed. They reverentially addressed the prime minister as "Vladimir Vladimirovich".

Putin's eighth annual phone-in was screened live on Russian TV and entitled A Conversation with Vladimir Putin: The Sequel. The event is an opportunity for Putin to demonstrate his stamina, charm and mastery of local detail. Hostile questions are weeded out – with pre-selected factory workers and studio guests "spontaneously" picked instead.

Putin said the threat of terrorism in Russia remained extremely high after 26 people were killed last week when their luxury express travelling between Moscow and St Petersburg was apparently blown up. He promised to "break the spine" of the criminals responsible.

He signalled that the peak of Russia's economic crisis had passed, though he acknowledged the country still faced economic challenges, particularly in single industry Soviet-era towns. He addressed other voter-friendly concerns such as pensions, hospitals, and the future of Russia's struggling car and aviation industries.

The prime minister fielded inquiries on more light-hearted subjects. They included Russia's failure to qualify for the World Cup next year in South Africa, breakdancing and rappers. Putin said Russian rappers were more responsible than western ones. Asked whether he liked animals, he talked keenly about Russia's tigers and leopards, and the uncertain fate of the country's Arctic polar bears.

PutinHe also waded into the debate on Stalin – the subject of a row this year between Russia and its eastern European partners. The Stalin era saw Soviet Russia's transformation from an agrarian to an industrial state, he said, as well as its victory in the second world war. "If the war had been lost the consequences would have been catastrophic," he reminded his audience.

But he added: "All these positive things were achieved at an unacceptable price. Repression was real. Millions suffered from repressions. We can't forget the cult of personality or the crimes against Russia's own people. The era must be analysed in its complexity."

Putin made a few polite references to Medvedev – pointing out they had shared the same teacher at the same university in St Petersburg, who had imbued them with common values. Medvedev has recently criticised the state of Russia in a series of gloomy speeches. An upbeat Putin, by contrast, implied that all is well. He offered practical help to the country's citizens, promising new school computers to one caller.

He Putin was reticent about foreign policy, formally Medvedev's brief. But he said Russia had no evidence that Iran was trying to build a nuclear weapon and declined to say whether Moscow would back sanctions. He praised the former US president George Bush as a "decent and good guy" and said he would be happy to meet him again.

He said he wanted warm relations with Ukraine and blamed Ukraine's pro-western president, Viktor Yushchenko, for the uncomfortable stand-off between Moscow and Kiev.

Only one subject roused Putin to anger: Mikhail Khodorkovsky. The oligarch was arrested in 2003 and jailed for eight years in a case most observers believe was politically motivated: Khodorkovsky had challenged Putin by funding opposition political parties. The former billionaire is currently on trial facing fresh charges that could bring 22 more years in prison.

Asked whether Khodorkovsky should be freed, Putin replied: "It isn't a question of whether he should be released but how to prevent crimes of this kind in future."

Putin said economic criminals should be dealt with in accordance with Russian law. In reality, however, this is little guarantee of justice as Russia's judges do what they are told by the Kremlin.

Putin confirmed the widespread view that his era has a long time to run – possibly until 2024, by when he would have served two more presidential terms. Asked by Leonard from Krasnodar whether he planned to spend more time with his family, Putin broke into a twinkling half-smile. He said: "Don't hold your breath."

Political analyst Stanislav Belkovsky, the founder and director of Moscow's National Strategy Institute, said it remained unclear whether Putin would return as president. "The question of who will be the next president won't be decided until early 2011. It won't be decided by Putin, or by Putin and Medvedev, but by Russia's political elite. At the moment the elite wants Medvedev because Medvedev allows them to keep their assets in the west – and is associated with the reset in relations with the US and other geo-political partners. Ultimately the elite decides, not Putin.

"In my opinion Putin is becoming more and more separated from the rest of the country. He doesn't know what is happening in the economic and social sphere. The event was stage-managed much better than last year, with 99% of the questions prepared in advance. The facts and figures were all ready for him."

Putin on Russia's wealth

The behaviour of Russia's rich has been in the headlines since a young Russian crashed his Lamborghini last month while racing along the banks of Lake Geneva. The Russian seriously injured a German pensioner in a VW Golf. Three other Russians were allegedly involved. One of them was driving a Bugatti Veyron, at £1.3m the world's most expensive car. "The nouveaux riches all of a sudden got rich very quickly but cannot manage their wealth without showing it off all the time. Yes, this is our problem," Putin told Russia's citizens . "Today's situation is similar to Soviet times when it was fashionable to show off your wealth by having gold teeth."